The last time we heard about the Marie Antoinette Blue Diamond was in 1983, when the celebrated diamond came up for auction at Christie’s, Geneva, but was not sold. Hence, the diamond apparently remains with the same private collector from Europe, who purchased it in 1967, at the Palais Galliera in Paris.
The Marie-Antoinette Blue Diamond, is a 5.64 carat, blue, heart-shaped diamond which the queen had set in a ring.The queen is said to have given the ring to her close friend, the Polish Princess Lobomirska, shortly before her trial in 1791. After the Polish princess died her estate was passed to her four daughters. The diamond became the property of Count Vladimir Potocki through his marriage to one of the daughters. The blue diamond was displayed at a number of prestigious exhibitions throughout the 19th century,

Given the period of origin of the Marie Antoinette Blue Diamond as mid 18th-Century and the color of the diamond is fancy grayish-blue, the most probable mine of origin of the celebrated diamond, is the Golconda Mines situated on the eastern side of the Deccan in Southern India, in the lower region of the Kistna river basin, and include some of the oldest and most famous of Indian diamond mines, such as the Kollur mines and Parteal mines. Diamonds were first discovered in Kollur around 1560. The main source of blue diamonds in the world in ancient times was the Kollur Mines of Golconda. Famous historic blue diamonds like the Hope diamond, Tereschenko diamond, Wittelsbach-Graff diamond,Sultan of Morocco diamond and the Brunswick Blue diamond, all originated in the Kollur Mines of Golconda. In the mid 18th-Century, when the Marie Antoinette Diamond first appeared, the only source of blue diamonds in the world was the Kollur Mines of Golconda, and hence the most probable source of the Marie Antoinette Diamond was these mines.

Although, the diamonds mines of Brazil were discovered around 1725, and significant quantities of colorless diamonds entered the diamond markets of the world in the mid and late 18th-Century, the discovery of a significant blue diamond has never been reported from Brazil. On the other hand several extremely rare red diamonds have been reported from Brazil, such as the Mousaieff Red, Rob Red diamond etc. According to Rafal Swiecki, geological engineer, 40 per cent of Brazilian diamonds are completely colorless of which 25 per cent are of the purest water and top quality. About 30 per cent show a slight tinge of color, and though the remaining 30 per cent have a pronounced color, stones of a deep and beautiful shade are rare. The colors which have been observed in Brazilian stones are yellow, red, brown, green, gray, and various shades of black; blue is rare, but a few stones showing a beautiful shade of this color are said to have been found.

Being Golconda diamonds the 45.52-carat, antique cushion brilliant-cut, Hope diamond and the 5.46-carat, heart-shaped Marie Antoinette Blue Diamond share almost the same color, fancy grayish-blue color, but the Hope diamond is a little darker in color and described as a fancy dark grayish blue color.

The List of known famous blue diamonds in the world arranged in descending order of carat weights, which includes the Hope diamond, Tereschenko diamond, Wittelsbach-Graff diamond, Sultan of Morocco diamond, the Brunswick Blue diamond, Marie Antoinette Blue diamond etc. can be seen by clicking the link below :-